How Does Changing Distance Affect Microwave Path Difference?

[heroslayer99]

Homework Statement

Show that the student is correct.

Relevant Equations

x

I understand the equation (path difference)/wavelength x 2pi = phase difference, but in this case I do not know how changing the distance of H from the source will affect the path difference. In addition to this, does minima refer to 0 amplitude (complete destructive interference) or does minima just refer to less than maxima? Does a path difference of lambda/2 gurantee the resulting signal has 0 amplitude?

 

[BvU]

Hi,

Zero amplitude can only be achieved when equal amplitude waves interfere. Here, all you are given is that H is a partial reflector.

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[heroslayer99]

Hi,

Zero amplitude can only be achieved when equal amplitude waves interfere. Here, all you are given is that H is a partial reflector.

$\$

Ok thanks. Any tips on how to do the question

 

[haruspex]

Ok thanks. Any tips on how to do the question

What should be the received frequency of the reflections from the moving plate?

 

[heroslayer99]

I dont know, 200hz?

 

[haruspex]

I dont know, 200hz?

Have you never learnt about the Doppler effect with sound waves?

 

[heroslayer99]

No, also aren't these microwaves

 

[Steve4Physics]

No, also aren't these microwaves

You are missing the point!

Tip: find out what 'Doppler radar' is and how it works. Then see if you can apply your new found knowledge to this problem Then ask us to check/advise.